This book has long been hailed as a classic and authoritative text. This latest edition examines the developments and challenges of modern diplomacy through new chapters on human rights and public/digital diplomacy.

The Vienna Convention on the Law of Treaties (or VCLT) is a treaty concerning the international law on treaties between states. It was adopted on 22 May 1969 and opened for signature on 23 May 1969. The Convention entered into force on 27 January 1980.